I've dabbled in some of these listed below but haven't seriously incorporated them into my food production methods........
Drip irrigation. I think that drip irrigation is a great way to go for large garden beds. But I've got a number of problems with it. There would be a lot of equipment to purchase...hoses, pipe, emitters (if used), connectors, pressure valves, water tanks, pumps. And I'd need a filtration system for my rainwater before sending it through a drip system. And the labor would be a factor because I would need to remove the water lines between harvested and next seeded crops so that the soil could be prepped for the next planting. On top of it, my growing beds are not located in one huge central garden plot. They are scattered about the homestead in small garden locations. Some day I plan to toy with some sort of drip irrigation set-up for at least part of the gardens. Something hopefully simple and not expensive.
Foliar feeding. I've been impressed with the results a nearby commercial farmer has had with foliar applications. It's something I've been considering experimenting with. Some day.
Vertical gardening. During visits to other gardens, I've seen some examples of vertical gardening. I really don't need to worry about running out of growing space on my farm, but vertical gardening still looks like something fun to toy with.
Greenhouses for wind protection and rain exclusion. Certain veggies here do far better in a greenhouse. Slicing tomatoes. Summer squash. Peppers. So I'd like to make a small greenhouse some day.
Screen house gardening for controlling insect problems. Some veggies are nearly impossible to grow because of pests. I plan to try cucumbers and some squash in a screen house and see if that helps. Maybe il try a slicing tomato too.
Hand pollinating. This is something I already know how to do, but I haven't put much time into it thus far. But I'm interested in saving my own seed, so I'm going to set up little projects to hand pollinate certain crops so that I can save the seed.
Creating my own hybrids and varieties. Now this could be pure fun!
Selecting for landrace. I'm just starting to do this already with pumpkins. Eventually I'll end up with pumpkins that grow exceptionally well on my farm because they are the survivors of the local bugs and diseases.
Aquaponics. Right now my ag catchment tanks and ponds host mosquito eating fish and tilapia. So I do already have a source of water for a small aquaponics system. Currently the only thing plant-wise growing in the ponds is water hyacinth. It might be cool to be growing lettuce instead.
Circulating hydroponics. The only hydroponics that I've done to date has been non-circulating systems. These systems work great for quick growing lettuce. But I'd like to design a simple circulating system and expand into growing other greens and strawberries.